Trust IS gained over time - BUT we have to be sure that the person who we're trying to get the trust FROM is willing to GIVE it -- and I'm not sure he is.
I think he's decided (he may not even be aware of it) that he's never going to trust a woman again. You're going to be walking on egg shells from now on, after this last incident, never knowing what's going to set him off.

I would NOT want to have to live like that. How are you going to know what reminds him of previous incidents? Are you a mind-reader?
This makes it impossible to BE open and honest with him, for fear of either hurting his feelings, reminding him of something from the past, etc. Like I said, you'll be walking on egg shells. No thanks.....that wouldn't be for me.
Perhaps counseling will help. Maybe the counselor will help him get past his previous hurts. It's worth a try. Best of luck and God bless. Hugs, Lee